OBJECTIVES: This systematic literature review discusses the efficacy and safety of botulinum toxin type A (Botox) intradetrusor injections in adults with neurogenic detrusor overactivity (NDO) and urinary incontinence or overactive bladder symptoms of neurogenic origin (NOAB).METHODS: A MEDLINE and EMBASE search for clinical studies with botulinum toxin A injected into the detrusor of adults with NDO was performed. For several efficacy and safety variables data were extracted by one person and independently quality-controlled by another person. Extracted data were reviewed to propose recommendations for use in clinical practice based on level of evidence and expert opinion.RESULTS: A total of 18 articles evaluating the efficacy or safety of Botox in patients with NDO and incontinence/NOAB resistant to antimuscarinic therapy, with or without clean intermittent self-catheterisation (CIC), were selected. The amount of Botox injected was mostly 300 U, usually as 30 injections of 10 U/ml in the bladder (excluding the trigone) under cystoscopic guidance and with different types of anaesthesia. Most of the studies reported a significant improvement in clinical (approximately 40-80% of patients became completely dry between CICs) as well as urodynamic (in most studies mean maximum detrusor pressure was reduced to < or =40 cm H(2)O) variables and in the patients' quality of life, without major adverse events.CONCLUSIONS: Botox injections into the detrusor provide a clinically significant improvement in adults with NDO and incontinence/NOAB refractory to antimuscarinics. It seems to be very well tolerated. However, more adequately powered, well-designed, randomised, controlled studies evaluating the optimal dose, number and location of injections, impact on antimuscarinic regimen and CIC use, duration of effect, and when to perform repeat injections are warranted.